DIY: Fang Vents: Forced fresh air to your airbox

GreenJalapeno

great great write up!


"The hotter the air the greater tendency for detonation so the ECU dials things back. Forcing some cool air in there brings temps down quickly and effectively."

however, i think the reason for the detonation of colder air is better since its denser, not to cool the engine (although its a good side affect). In hot air, molecules tend to be excited and loosely packed (as in vibrating and bumping into each other, leaving spaces in between the molecules), while colder air leaves molecules tightly formed. This means denser and richer air, which ultimately means more fuel will be allowed to burn.

Modshack

I think you meant to say
"Hotter" there, but yes, I agree. It's about the ability to use denser air that will combust in the proper A/F range. Leaner = hotter. When a MAF IAT sensor detects overly hot air, the timing maps are rolled back along with performance. Cooler is always better..

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racerxj17

just to clarify, cooler air (denser) will make the A/F go leaner, and hotter air will make the car run richer.

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Modshack

Yeah, sorry..That is correct, but the 02 sensors downstream are always correcting for that. It's the timing that imposes the performance hit..

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ZYUL8R

Yes, the ECU gets a hot Intake temperature it cuts fuel to keep the A/F ration in place, which robs performance.

With cooler Intake temperatures it doesn't do that.

Ever notice your car running good on a cold day...its the ECU giving more fuel to burn with the denser air.

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Modshack

Well....Close but......

Fuel is always being adjusted no matter what the temperature. This is handled downstream by the 02 sensors which are constantly making minor corrections to A/F based on Measured data from both sampling, and the MAF flow information. They don't care what the Intake temps are, they are just concerned with keeping things in line. There are Short term trims (imediate minor changes happening all the time), and long term trims, (that build up a reference map based on the overall conditions). Heat and IAT temps largely affect timing maps in most modern ECU's...They dial back timing as a protective measure.. The performance loss you experience is largely this adjustment. Fuel continues to be held at or around stochiometric (14.7:1 A/F) as long as you're in Closed loop mode (not WOT Open loop which uses pre-built Fuel maps and ignores 02 input). Here's an IAT and timing adjustment chart from an '08 Corvette. Notice how, at temps, over a mere 86 degrees, a timing retard starts being implemented...As a reference, it is not unusual to see the IAT's on the Z exceed 150 degrees when sitting in traffic. On the Vette chart, that's an average -6 to -8 degree timing pullback

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ZPirate

Looks good Steve. Perhaps I can check out your latest creation this weekend.

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Modshack

Yup! Lets get together!

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aj.nguyen

Where did u buy all the materials?